Muffler



F. B. RICHMOND.

MUFFLER. APPLICATlON FILED MAR-27. 1920.

1,365,852 Patented Jan. 18, 1921.

UNITED STATES PATENT OFFICE.

FRANK B. RICHMOND, OF CAMDEN, NEW JERSEY.

MUFFLER.

' To all whom it may concern:

Be it known that I, FRANK B. RICHMOND, a citizen of the United States, residing in Camden, New Jersey, have invented Mufliers, of which the following is a specification.

One object of this invention is to provide a relatively simple, substantial, and inexpen sive device partlcularly adapted to serve as a silencer or muffler for an internal combustion engine; the invention especially contemplating an arrangement of parts whereby the back pressure on the engine with which it is associated shall be materially reduced from that existing in its absence.

It is further desired to provide a novel arrangement of parts for delivering the exhaust gases from an internal combustion engine to the air in the form of a relatively narrow ring of comparatively large diameter, with a view to preventing noise without causing the back pressure ordinarily occurring when a silencer or a muflier is employed; the invention more especially including an automatically acting valve for insuring the maintenance of a partial vacuum in the exhaust conduit of the engine.

Another object of my invention is to provide a device of the character noted which shall be convenient to attach to the exhaust pipe of the engine and which shall automatically perform its functions without requiring attention and with but little need for repairs or inspection.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had tothe accompanying drawings, in which,

Figure 1 is a side elevation illustrating my deviceas applied to the exhaust conduit of an internal combustion engine;

Fig. 2 is a longitudinal vertical section of the muffler; and

Fig. 3 is an end elevation of the device shown in Fig. 2.

In the above drawings 1 represents a tubular body designed for connection to an exhaust conduit of an internal combustion engine and having formed integral with it a flaring or funnel shaped outlet 2. Within this latter is mounted a second flaring or funnel structure 3 whose external conical wall is spaced away from the internal conical wall of said outlet 2 by a suitable number of lugs 4, the angle between the wall of this inner structure and its longitudinal axis being greater than that between the latter Specification of Letters Patent.

Patented Jan. 18, 1921.

Application filed March 27, 1920. Serial No. 369,411.

and the inner wall of the structure 2. As a result, the walls of the structures 2 and 3 converge as they expand although the cross sectional area of the passage between them in any plane at right angles to the axis of the structure remains substantially constant.

Adjacent the point of junction of the parts 1 and 2 I provide a seat for a valve 5 having a stem 6 guided axially of the device by a bearing '7 and normally pressed toward said seat by a coil tions of operation the products of combustion from the engine to which the exhaust pipe 9 is connected raise the valve 5 from its seat at each explosion, thus permitting their escape through the diverging passage 10 between the structures 2 and 3.

Immediately after the discharge of each body of gas from the exhaust pipe of the engine, the spring 8 causes the reseating of the valve 5 and I have found that not only does the device act to effectually silence or prevent the noise of the explosions, but it also reduces the back pressure on the engine, it being found that the speed of the latter is increased when my device is connected to its exhaust pipe, other conditions remaining the same.

I have found that to obtain the best results the exhaust pipe between the engine and the valve of my device should possess a volume or capacity approximately three times that of any one combustion chamber of the engine with which it is associated, for under these conditions not only is the exhaust of successive explosions delivered noiselessly to the air, but there is a partial vacuum created in said exhaust pipe which materially reduces the back pressure on the engine.

- I claim:

1. The combination of a tubular structure for connection to the exhaust pipe of an engine and provided with a conical outlet; a valve mounted at the apex of said outlet; a conical member rigidly mounted within the outlet and spaced away from the inner surface thereof to provide an annular passage of decreasing width; and means carried by said conical member tending to automatically close the valve after the passage of each body of exhaust gas from the engine.

2. The combination of a tubular structure having a flaring outlet and adapted to be spring 8. Under condi-' said structure at the apex thereof in position fiaring outlet of said first structure and spaced away from the same to provide a passage; and a valve positioned to control the entrance of exhaust gases to said passage.

4:. The combination of a tubular structure adapted to be connected to the exhaust of an engine and having a conical outlet; a valve mounted at the apex of said outlet in position to be opened by successivebodies of exhaust gasdelivered to said structure; with a second conical structure rigidl mounted Within and spaced away from t e wall of the first structure to provide an annular orifice for the delivery of the gas to the atmosphere. I

5. The combination of a tubular structure having a conical outlet portion; a conical structure rigidly mounted within and spaced away from the walls of said conical portion of the first structure to form a channel of decreasing width but of substantially constant cross sectional area; a valve mounted in position to be opened by exhaust gases entering the tubular structure; with a spring normally holding said valve closed.

FRANK B. RICHMOND. 

